In the current second-generation (2G) and third-generation (3G) cellular systems, radio link resource allocation for user equipment is based on radio bearers that are configured using control signalling. A radio bearer is a service provided by a communication layer (e.g., Layer 2) for the transfer of user data between the user equipment and the wireless network. No user data can be exchanged before the radio bearer has been established. While the radio bearer is in use, changes in radio attributes for the radio bearer (e.g. maximum supported data rate) must be configured using control signalling. Additionally, the radio bearer must be released when it is no longer needed. Depending on the delay requirements of the radio bearer, radio link resources may be permanently allocated during the existence of the radio bearer.
Packet-based services have in present-day cellular systems been implemented “on top of” end-to-end configured bearers. While such bearers are suitable for primarily circuit-switched traffic such as voice, in a packet-based system their significance decreases. This is true because packet-based services are highly dynamic in nature, as opposed to being continuous. In the context of packet-based services, a pre-established radio bearer that reserves certain radio link resources only for one user will waste overall network resources, if the reserved radio link resources are not continuously in efficient use.
Also, radio bearer establishment signalling in the beginning of a connection between the user equipment and the network increases perceived latency for packet-based services. In general, radio bearer management in a wireless network increases the complexity of the network at system level. This problem has been identified, e.g., in the third generation partnership project (3GPP), where shorter set-up latency has been requested by many vendors and operators.
Thus improvements could be made to wireless networks carrying packet traffic.